1. Field of the Invention
The present invention relates to a radiographic apparatus and a radiographic method.
2. Description of the Related Art
In recent years, flat panel detectors (FPD) that comprise an X-ray sensitive layer disposed on a thin-film transistor (TFT) active matrix substrate and can directly convert X rays into digital data have been put to practical use. Portable radiographic image detection devices (called “electronic cassettes” below) that use an FPD or the like to generate image data, which represent a radiographic image expressed by radiation that has been transmitted through a subject such as an examinee and with which the subject has been irradiated, and store the generated image data have been put to practical use.
As a radiographic apparatus that acquires, as a digital image, X rays that have been transmitted through a subject in this manner, in Japanese Patent Application Laid-Open Publication (JP-A) No. 2002-204794, there is disclosed an apparatus that controls the movement of a tube that outputs radiation depending on the type of apparatus that generates radiation and the aperture of an irradiation field.
In JP-A No. 2005-198975, there is disclosed a technology that reduces halation on an image caused by a mechanical shift in an X-ray irradiation field aperture or the like.
As a technology that manages radiation amounts, in JP-A No. 2007-181686, there is disclosed a technology that creates patient radiation amount measurement information on the basis of radiation amount measurement data of radiation to which a patient has been exposed.
In JP-A No. 2004-201757, there is disclosed a technology that determines, by calculation, amounts of X rays with which an examinee has been irradiated and stores and manages the cumulative value of the X-ray amounts.